1. Technical Field
The present disclosure relates to anode active materials. Specially, the present disclosure relates to phosphorus composite material as the anode active materials.
2. Description of Related Art
Anode active materials are the main components of lithium ion batteries. Elemental phosphorus as anode active material has a theoretical specific capacity of about 2594 milliamp hours per gram (mAh/g), which is much higher than the theoretical specific capacities of graphite (372 mAh/g) and elemental tin (992 mAh/g).
The elemental phosphorus has three major allotropes: white phosphorus, red phosphorus, and black phosphorus. Among these allotropes, white phosphorus is chemically unstable. Black phosphorus is the most thermodynamically stable, but difficult to synthesize. Red phosphorus is stable and abundant in nature, and has a low cost. However, because of its electronic insulation, an experimental capacity of the red phosphorus is far lower than the theoretical value and fades considerably after a few cycles.
What is needed, therefore, is to provide a method for making an anode active material using the red phosphorus which can overcome the electronic insulation of the red phosphorus and improve the capacity and stable cycling of the red phosphorus.